18-letter words containing o, l, r, s
- ultrasound scanner — a device used to examine an internal bodily structure by the use of ultrasonic waves, esp for the diagnosis of abnormality in a fetus
- under (one's) seal — in a document authenticated by one's seal
- universal coupling — a coupling between rotating shafts set at an angle to one another, allowing for rotation in three planes.
- ur of the chaldees — the city where Abraham was born, sometimes identified with the Sumerian city of Ur. Gen. 11:28, 31; 15:7; Neh. 9:7.
- uriniferous tubule — a urine-bearing tubule in a nephron of a kidney.
- vermilion rockfish — a scarlet-red rockfish, Sebastes miniatus, inhabiting waters along the Pacific coast of North America, important as a food fish.
- video surveillance — a system of monitoring activity in an area or building using a television system in which signals are transmitted from a television camera to the receivers by cables or telephone links forming a closed circuit
- watson-crick model — a widely accepted model for the three-dimensional structure of DNA, featuring a double-helix configuration for the molecule's two hydrogen-bonded complementary polynucleotide strands.
- western alienation — a feeling of resentment by some inhabitants of western Canada against perceived favouritism by the national government towards the eastern provinces
- western isles pony — a breed of large pony, typically grey, with a dense waterproof coat. The only surviving variety is the Eriskay pony
- western meadowlark — any of several American songbirds of the genus Sturnella, of the family Icteridae, especially S. magna (eastern meadowlark) and S. neglecta (western meadowlark) having a brownish and black back and wings and a yellow breast, noted for their clear, tuneful song.
- wheelchair housing — housing designed or adapted for a chairbound person
- wild passionflower — the maypop, Passiflora incarnata.
- wilson's phalarope — a phalarope, Phalaropus tricolor, that breeds in the prairie regions of North America and winters in Argentina and Chile.
- wireless telephone — Now Rare. radiotelephony.
- wireless telephony — Now Rare. radiotelephony.
- with flying colors — with flying colors, with an overwhelming victory, triumph, or success: He passed the test with flying colors.
- withdrawal symptom — effects of stopping a drug
- women's liberation — a movement to combat sexual discrimination and to gain full legal, economic, vocational, educational, and social rights and opportunities for women, equal to those of men.
- working men's club — A working men's club is a place where working people, especially men, can go to relax, drink alcoholic drinks, and sometimes watch live entertainment.
- world championship — an international competition in a particular sport or activity for people all around the world
- world of one's own — a state of mental detachment from other people
- wrangell mountains — a mountain range in SE Alaska, extending into the Yukon, Canada. Highest peak: Mount Blackburn, 5037 m (16 523 ft)
- wrongful dismissal — the act of making someone redundant for reasons which are illegal or unjust
- yelloweye rockfish — a red rockfish, Sebastes ruberrimus, of waters along the Pacific coast of North America, having eyes that are yellow and possessed of strong, sawlike bony ridges on the head.
- zermelo set theory — (mathematics) A set theory with the following set of axioms: Extensionality: two sets are equal if and only if they have the same elements. Union: If U is a set, so is the union of all its elements. Pair-set: If a and b are sets, so is {a, b}. Foundation: Every set contains a set disjoint from itself. Comprehension (or Restriction): If P is a formula with one free variable and X a set then {x: x is in X and P(x)}. is a set. Infinity: There exists an infinite set. Power-set: If X is a set, so is its power set. Zermelo set theory avoids Russell's paradox by excluding sets of elements with arbitrary properties - the Comprehension axiom only allows a property to be used to select elements of an existing set.